/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.tsfile.file.metadata.statistics;

import org.apache.iotdb.tsfile.exception.filter.StatisticsClassException;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.utils.Binary;
import org.apache.iotdb.tsfile.utils.RamUsageEstimator;
import org.apache.iotdb.tsfile.utils.ReadWriteIOUtils;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.util.Objects;

/**
 * Statistics for string type.
 */
public class BinaryStatistics extends Statistics<Binary> {

    private Binary firstValue = new Binary("");
    private Binary lastValue = new Binary("");
    static final int BINARY_STATISTICS_FIXED_RAM_SIZE = 32;

    @Override
    public TSDataType getType() {
        return TSDataType.TEXT;
    }

    /**
     * The output of this method should be identical to the method "serializeStats(OutputStream
     * outputStream)"
     */
    @Override
    public int getStatsSize() {
        return 4 + firstValue.getValues().length + 4 + lastValue.getValues().length;
    }

    /**
     * initialize Statistics.
     *
     * @param first the first value
     * @param last  the last value
     */
    public void initializeStats(Binary first, Binary last) {
        this.firstValue = first;
        this.lastValue = last;
    }

    private void updateStats(Binary firstValue, Binary lastValue) {
        this.lastValue = lastValue;
    }

    private void updateStats(Binary firstValue, Binary lastValue, long startTime, long endTime) {
        // only if endTime greater or equals to the current endTime need we update the last value
        // only if startTime less or equals to the current startTime need we update the first value
        // otherwise, just ignore
        if (startTime <= this.getStartTime()) {
            this.firstValue = firstValue;
        }
        if (endTime >= this.getEndTime()) {
            this.lastValue = lastValue;
        }
    }

    @Override
    public Binary getMinValue() {
        throw new StatisticsClassException(
                String.format(STATS_UNSUPPORTED_MSG, TSDataType.TEXT, "min"));
    }

    @Override
    public Binary getMaxValue() {
        throw new StatisticsClassException(
                String.format(STATS_UNSUPPORTED_MSG, TSDataType.TEXT, "max"));
    }

    @Override
    public Binary getFirstValue() {
        return firstValue;
    }

    @Override
    public Binary getLastValue() {
        return lastValue;
    }

    @Override
    public double getSumDoubleValue() {
        throw new StatisticsClassException(
                String.format(STATS_UNSUPPORTED_MSG, TSDataType.TEXT, "double sum"));
    }

    @Override
    public long getSumLongValue() {
        throw new StatisticsClassException(
                String.format(STATS_UNSUPPORTED_MSG, TSDataType.TEXT, "long sum"));
    }

    @Override
    protected void mergeStatisticsValue(Statistics<Binary> stats) {
        BinaryStatistics stringStats = (BinaryStatistics) stats;
        if (isEmpty) {
            initializeStats(stringStats.getFirstValue(), stringStats.getLastValue());
            isEmpty = false;
        } else {
            updateStats(
                    stringStats.getFirstValue(),
                    stringStats.getLastValue(),
                    stats.getStartTime(),
                    stats.getEndTime());
        }
    }

    @Override
    void updateStats(Binary value) {
        if (isEmpty) {
            initializeStats(value, value);
            isEmpty = false;
        } else {
            updateStats(value, value);
        }
    }

    @Override
    void updateStats(Binary[] values, int batchSize) {
        for (int i = 0; i < batchSize; i++) {
            updateStats(values[i]);
        }
    }

    @Override
    public long calculateRamSize() {
        return RamUsageEstimator.sizeOf(this);
    }

    @Override
    public int serializeStats(OutputStream outputStream) throws IOException {
        int byteLen = 0;
        byteLen += ReadWriteIOUtils.write(firstValue, outputStream);
        byteLen += ReadWriteIOUtils.write(lastValue, outputStream);
        return byteLen;
    }

    @Override
    public void deserialize(InputStream inputStream) throws IOException {
        this.firstValue = ReadWriteIOUtils.readBinary(inputStream);
        this.lastValue = ReadWriteIOUtils.readBinary(inputStream);
    }

    @Override
    public void deserialize(ByteBuffer byteBuffer) {
        this.firstValue = ReadWriteIOUtils.readBinary(byteBuffer);
        this.lastValue = ReadWriteIOUtils.readBinary(byteBuffer);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        if (!super.equals(o)) return false;
        BinaryStatistics that = (BinaryStatistics) o;
        return Objects.equals(firstValue, that.firstValue) && Objects.equals(lastValue, that.lastValue);
    }

    @Override
    public int hashCode() {
        return Objects.hash(super.hashCode(), firstValue, lastValue);
    }

    @Override
    public String toString() {
        return super.toString() + " [firstValue:" + firstValue + ",lastValue:" + lastValue + "]";
    }
}
